The aims of this project are: 1) to study cell-mediated immune mechanisms in human glomerulonephritis utilizing the in vitro lymphocyte response to glomerular basement membrane antigens and the macrophage aggregation assay, and 2) to isolate and characterize the antigens from human glomerular basement membranes and to study the excretion of specific GBM antigens in normal individuals and patients with renal diseases.